The use of internal standard for quantitation of DNA and protein adducts of BPT was standardized, using Benzodiphenylene sulfides as an internal standard. Adducts can be detected with this technique in the subfemtomole ramge. Several DNA and histone adducts from same tissue samples we analyzed by this method to see the correlation between the two types of adducts. To detect and quantify the molecular fragments to which BPT gets addcuted, an HPLC system with fluorescence detection has been setup using 325 nm He-Cd laser excitation. Atto mole amunts of BPT could be detected with the HPLC-Fluorescnece technique.